Fermentation-assisted enzymatic hydrolysis improves the antioxidant activity of egg white peptides

Abstract

To obtain bioactive peptides from egg white, fermentation-assisted enzymatic hydrolysis (FAEH) was optimized using response surface methodology, and the antioxidant activity was evaluated by chemical and cytological assays and in Caenorhabditis elegans model. Results showed that the optimum conditions were fermentation time at 6.25 h, fermentation temperature at 33.27 °C, and pH at 5.33, under which the FRAP value was 4.65 times that of unfermented egg white peptides (EWP). The antioxidant activity of peptides less than 3 kDa (PLMW) after ultrafiltration was the highest, which had a high DPPH (80.05 ± 0.17 %) and ABTS (82.92 ± 0.72 %) scavenging ability, increased levels of intracellular SOD and GSH of Caco-2 cells, reduced the production of ROS, O^2- and lipofuscin, and promoted the production of GSH, POD, and CAT in Caenorhabditis elegans. Taken together, FAEH could improve the antioxidant activity of EWP, and PLMW had good antioxidant activity, which may be used in nutraceuticals and functional foods.